• Restorative Dentistry and Endodontics
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• v.41 no.4
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• pp.283-295
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• 2016

Objectives: In this study, we characterized human dental pulp cells (HDPCs) obtained by different culture methods to establish the most suitable methodology for dental tissue engineering and regenerative endodontic applications. Materials and Methods: HDPCs were isolated by the outgrowth method (HDPCs-OG), the enzymatic digestion method (collagenase/dispase/trypsin, HDPCs-ED), or the combination of both methods (HDPCs-Combined). The expression of mesenchymal stem cell markers (CD105, CD90, and CD73) was investigated. In vitro differentiation capacities of HDPCs into adipogenic, osteogenic, and chondrogenic lineages were compared. Differentiation markers were analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and western blotting. Results: Our data indicated that whole HDPCs-ED, HPDCs-OG, and HDPCs-Combined could be differentiated into adipogenic, chrondrogenic, and osteogenic cell types. However, we found that the methods for isolating and culturing HDPCs influence the differentiation capacities of cells. HDPCs-OG and HDPCs-ED were preferably differentiated into adipogenic and osteogenic cells, respectively. Differentiation markers shown by RT-PCR and western blotting analysis were mostly upregulated in the treated groups compared with the control groups. Conclusions: Our findings confirmed that cell populations formed by two different culture methods and the combined culture method exhibited different properties. The results of this study could provide an insight into regenerative endodontic treatment using HDPCs.

• ALGAE
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• v.21 no.2
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• pp.261-266
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• 2006

The innate soluble polysaccharides and phenolic compounds of marine macroalgae are serious contaminants which interfere with experimental procedures such as restriction enzyme digestion, polymerase chain reaction (PCR) and other enzymatic reactions using extracted DNA samples. The viscous polysaccharides are co-precipitated with DNA samples by isopropanol or ethanol precipitation in conventional experiment. To overcome the problem, a method for the isolation of high molecular weight DNA from Porphyra tenera is developed with the application of diatomaceous earth column. The isolated DNAs by this method were about 50-100 kb in size and could be digested well with restriction enzymes. The nuclease activity seemed to be minimal, and high reproducibility in the arbitrary primed PCR for RAPD analyses was a distinctive feature. These results suggest that this method is very efficient in isolating nucleic acid from macroalgae including Porphyra.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.365-368
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• 2003

Hair follicles develop as a result of epithelial-mesenchymal interactions between epidermal keratinocytes and dermal cells. Moreover hair follicles constitute multiple cells that influence hair follicle development and cyclic activity. We isolated some cells using explantation and enzymatic digestion method from human scalp hair follicles. So we could culture some follicular cells, such as outer root sheath (ORS) cells, dermal papilla (DP) cells, dermal sheath (DS) cells, matrix cells and melanocyte.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.356-358
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• 2003

The use of cultured epidermal sheet grafts for large full-thickness wound has been tempered by weak points such as long culture periods, difficulty in handling the fragile sheets, high costs and the detachment of the skin cells from the culture dishes by enzymatic digestion. To overcome the drawback of epidermal sheet grafts, we have developed a transplantation method to spray the cultured human keratinocytes with the mixtures of rhEGF and fibrin gel matrix to the full-thickness wounds on the dorsum of the athymic mice to regenerate epithelial layers. Wound biopsies were retrieved at 7, 14 and 21 days after transplantation and retrieved biopsies were analyzed by histology and immunohistochemistry. Transplanted keratinocytes and EGF-fibriin gel accelerated wound regeneration compared with control groups. The technique developed in this study overcomes the drawbacks of the current cultured epidermal sheet grafts and accelerates epidermal wound healing.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.70-74
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• 1974

The round muscle of Korean cattle and squid muscle were cooked with various methods which were followed digestibility test by use of pepsin in-vitro, determination of amino nitrogen in the course of digestion procedure by using Formol method (AOAC) and influence of ether treatment for preminary test also examined. The results obtained were summarized as follows: 1. The order of digestibility values were demonstrated as follows: In case of beef, it was autoclaving, frying, raw, freezing, roasting, boiling and in case of squid muscle, it was raw, autoclaving, boiling, freezing, dry heating and roasting. 2. The amounts of amino nitrogen for beef and squid muscle were increased in proportion to digestibility value. 3. There were no significances in the digestibility between treating with ether and none of any treatment of beef and squid muscle in raw condition.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.166-171
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• 2004

In this study, we introduced enzymatic pretreatment method, together with ozone treatment for sludge digestion. We optimized the amount of enzyme and ozone, respectively for the successful sludge pretreatment. As a result, we found that as more enzyme is used, higher sludge hydrolysis efficiency was obtained. When we treated sludge by ozone ranging from 0.01g $O_3$/g SS to 0.04 g $O_3$/g SS without enzyme treatment, 0.04 g $O_3$/g SS showed the highest increase of SCOD. Meanwhile, when protease was used together with the same ozone dosage ranges, 0.03g $O_3$/g SS ozonation resulted in the highest increase of SCOD. The sludge pretreatment was optimized by controlling the amount of enzyme and ozone.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1128-1133
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• 1998

Extrusion cooking treatment was compared with autoclaving/cooling treatment for formation of enzyme resistant starch of high amylose corn starch (HACS). Effects of barrel temperature $(100^{\circ}C,\;120^{\circ}C,\;140^{\circ}C)$ and feed moisture content (25%, 35%, 45%) on extrusion processing in a co-rotating twin-screw extruder under fixed screw speed (100 rpm) were investigated by measuring enzyme resistant starch (RS) yield. RS yield were estimated by in-vitro pancreatin digestion method and enzymatic-gravimetric method using termamyl. Barrel temperature and yield of RS were negatively correlated and feed moisture content and yield of RS was positively correlated as determined by in-vitro pancreatin method. The highest yield (38.4%) of RS was obtained from HACS extrudate processed at the barrel temperature of $100^{\circ}C$ and the feed moisture content of 45%, while the yield of RS by 5 times of autoclaving/cooling was 25%. The yield of RS by in vitro pancreatin digestion method was 20.7% with high amylose corn starch and 8.2% with ordinary corn starch (CS), respectively, under the same extrusion condition (barrel temperature $120^{\circ}C$, feed moisture content 35%). At the same condition, the yields of RS by enzyme-gravimetric method were 14.6% with HACS and 6.8% with CS, respectively. The yield of RS increased during the storage at $4^{\circ}C$ for 4 weeks and the highest yield (60%) was obtained by the storage of HACS extrudates extruded at $100^{\circ}C$ and 45% feed moisture content.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.103-109
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• 2005

Isolation and primary culture technique of rabbit oral keratinocytes, and the study for effect of environmental factors on the cell growth were carried out in T75-flask. $1.92{\pm}0.59{\times}10^6$ viable cells were isolated by trypsin enzymatic digestion method from $0.25cm^2$ biopsy of rabbit oral mucosa. Primary culture with 10 mL of K-SFM containing 50 mg/L BPE, $5.0{\mu}g/L$ EGF and 0.15 mM $Ca^{2+}$ showed confluence after 8 days and doubling time was 2.54 days. Effect of medium types, medium volume and supplement types on the cell growth was investigated after the cultured keratinocytes had been harvested from primary confluence. Serum addition showed adverse effect and the increase of serum concentration didn't have an effect on the cell growth. The increase of medium volume decreased the cell growth. The increase of calcium concentration increased the cell growth and 2.0 mM was optimum value. In conclusion, when rabbit oral keratinocytes was cultured in T75-flask, the most effective conditions was to use 10 mL of K-SFM containing 50 mg/L BPE, $5.0{\mu}g/L$ EGF and 2.0 mM $Ca^{2+}$, and doubling time was 1.32 days. This study can provide the useful informations to develop a process and design a bioreactor for the culture of keratinocytes in human body like skin and cornea, as well as mucosa.